JP5882366B2 - Insulating sealing cap assembly for fastening parts - Google Patents

Description

  The present invention generally seals fasteners and / or substrate openings to prevent contact with and / or leakage of fluids contained within the substrate, or system components and / or contained within the substrate. The present invention relates to an insulating sealing cap for use with a fastening component or the like inserted into an opening formed in a selected substrate to protect the fluid from damage due to discharge or the like associated with the fastening component. More particularly, the present invention relates to an improved insulating sealing cap and related uses for attaching a relatively strong or sturdy yet lightweight sealing cap in a position that covers fastening components and associated substrate openings on the substrate. About.

  Generally, fastening parts such as nuts and bolts are attached to a board such as an outer plate of an aircraft in association with the board opening. In this regard, such fastening parts typically include a nut or nut plate on one side of the board opening, which receives a threaded bolt or the like and is fixedly engaged with the nut or nut plate. ing. In modern aircraft, system components such as electronic devices are often placed on one side of a board, such as internal system components mounted inside an aircraft fuselage. Apart from this, the substrate typically constitutes a wing structure or the like that forms one wall of an aircraft fuel tank containing corrosive and volatile aircraft fuel and possibly some water.

  In any case, it is highly desirable that these substrates and associated substrate openings, and fasteners, be sealed from contact with fluids such as system components and / or fuel or communication in either direction. That is, it is desirable to prevent fluid from leaking out of the fuel tank and contacting and corroding fasteners and / or leakage through the substrate opening. Similarly, it is desirable to prevent damage to system components and / or aircraft fuel supplies due to electrical discharges associated with fasteners. In addition, it is desirable to prevent such damage by providing a sealing insulation cap of a relatively robust design that can withstand normal maintenance procedures without damaging the sealing cap. In an aircraft environment, it is desirable to provide these important sealing insulation functions with a minimum of overall weight addition to maximize overall fuel efficiency.

  Accordingly, there is a need for an improved insulating hermetic protective cap for use on aircraft substrates and the like. The present invention fulfills these needs and provides further related advantages.

  In accordance with the present invention, an insulated sealing cap is provided for overlying and protecting a fastener or the like associated with a substrate opening on a selected substrate. The sealing cap includes an outer cap component partially filled with a selected sealant, and the outer cap component is surrounded by a fastening component such as a nut on one side of a selected substrate such as an aircraft skin. Assembling with an inner collet sized and shaped to fit relatively loosely but non-rotatably. The inner edge of the inner collet is seated on the substrate to substantially seal the substrate. The outer cap component is then moved toward the substrate to extrude the sealant in the form of a thin, substantially uniform insulating layer bonded to the extruded outer bead on the substrate and then cured. During and after cure of the sealant, tapered ribs on the inner collet effectively lock the outer cap part.

  In one preferred form, the outer cap part is partially filled with an amount of a selected sealant and then the inner collet is nested within the outer cap part. In this configuration, the assembled insulating cap can be quickly attached in such a manner that it covers the fastening parts on one side such as the blind spot side of the substrate and provides insulation protection. Alternatively, the assembled insulating cap can be refrigerated until use and preferably frozen to prevent the sealant from hardening immediately. In the latter case, the frozen insulating cap containing the sealant is thawed before use and preferably heated slightly.

  The assembled insulating cap is fitted over a fastening part such as a nut or nut plate that is adapted to receive a threaded bolt inserted into the opening of the board, and the inner edge of the inner collet side wall is placed on the board. Sit and seat in a substantially sealed relationship at a location circumscribing the fastening component and the associated substrate opening. The fitting between the inner collet of the assembled cap and the fastening part is preferably a sliding fit. In this initial configuration, the sealant remains mainly in the space between the closed end wall of the outer cap part and the inner collet.

  Next, the outer cap component is pushed downward, i.e., toward the substrate, and the sealant is pushed between the outer cap component and the inner collet toward the substrate. In this regard, the outer cap component and inner collet are preferably formed of a non-metallic material such as a relatively strong or sturdy, preferably selected, relatively lightweight molded plastic or fiber composite. Each of these interdigitated structures defines a substantially closed end wall coupled to a side wall, such as a generally cylindrical side wall, having a selected, preferably matching, tapered shape. Between these two interdigitated parts, an inner collet to effectively lock the interdigitated parts together while maintaining a desired and relatively narrow or uniform space between the side walls of the parts Tapered lock ribs such as external ribs formed on the inner collet that extend from the inner edge of the inner collet to about 1/2 the height of the side wall.

  When the inner edge of the outer cap component is seated on the substrate, a certain amount of sealant is selected so that the inner edge of the outer cap component contacts and seals the extruded sealant bead. It is important that this extruded bead effectively seal between the outer cap component and the substrate after a suitable curing time, regardless of the specific geometry of the substrate. In other words, depending on the substrate geometry, this extruded bead in some areas may need to be thicker than other areas.

  Thus, the resulting insulating cap assembly mounted in a relationship surrounding the fastening component on the substrate is sufficiently effective to overlay and protect the fastening component and the associated substrate opening. Provides a relatively thin and lightweight insulating seal. That is, the sealing cap may be a lightweight molded plastic with sufficient structural rigidity to withstand normal maintenance procedures without breakdown and / or damage that may undesirably interfere with the desired insulation and sealing function. Fig. 3 shows a constructed relatively sturdy cap structure. Similarly, the sealing cap insulates system components and / or fluid on the opposite side of the sealing cap from potential damage, such as due to discharges in the fasteners and / or through the substrate opening. Optionally, one of the outer cap part and the inner collet, eg, the inner collet, is constructed of at least partially conductive material to separate the fastening part from the aircraft internal part and / or the aircraft fuel supply. A shield can also be formed.

  Other features and advantages of the present invention will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

  The accompanying drawings illustrate the invention.

FIG. 3 is an exploded perspective view showing an outer cap part and an inner collet of an insulating sealing cap for mounting on a selected substrate and overlying and protecting a fastening part and the like. FIG. 5 is an upside-down fragmentary perspective view showing the outer cap part partially filled with a fixed amount of curable sealant. FIG. 5 is an upside-down perspective view showing an outer cap part in a assembled relationship with an inner collet. FIG. 4 is a perspective view showing a state in which the insulating sealing cap of FIGS. 1 and 3 is arranged so as to cover a fastening part that is previously attached on a substrate. FIG. 6 is an enlarged vertical cross-sectional view showing the initial placement of the insulating sealing cap on the substrate with the inner collet positioned over the nut or other fastener. FIG. 6 is an enlarged vertical sectional view showing a state in which the outer cap part is advanced downward toward the substrate with respect to the inner collet and the sealant is pushed out between the outer cap part and the inner collet, similar to FIG. 5. FIG. 7 is an enlarged vertical cross-sectional view similar to FIGS. 5 and 6 but showing the final extrusion movement of the sealant for protective overlap and sealing on a nut or other fastener on the substrate. FIG. 5 is a perspective view of an insulating protective cap similar to FIG. 4 but mounted on a substrate in a relationship to cover and protect nuts or other fastening components.

  As shown in the exemplary drawings, a diagram for insulating and sealing fasteners 12 such as the exemplary nuts shown in FIGS. 1 and 4-7 attached to one side of a selected substrate 14 An insulating sealing cap, generally designated by the reference numeral 10, is provided in FIG. Generally, the fastening component 12 is related to an opening or passage 16 (FIGS. 1 and 5 to 7) formed in the substrate 14, and a screw bolt 18 or the like is generally fitted in the opening or passage 16. The nut 12 and the screw are assembled. The insulating sealing cap 10 of the present invention overlies the fastening component 12 and the substrate opening 16 to contact system components (not shown) and / or fluid (also not shown) on the fastening component side of the substrate 14. These are protected from unwanted damage to the fastening part 12 due to In addition, the insulating sealing cap 10 of the present invention advantageously protects system components and / or fluids from damage, such as electrical discharge, due to the presence of a metal fastening component 12, usually. These bi-directional insulating sealing functions are advantageously provided by the cap 10 in a lightweight yet robust cap structure that facilitates quick and easy mounting onto the substrate 14.

  As shown in FIGS. 1 and 3, the insulating sealing cap 10 of the present invention comprises an outer cap component 20 having a generally cap-shaped preferred configuration that includes a substantially closed top wall 22 coupled to a depending side wall 24. In addition, this side wall 24 has a generally open lower edge 26 defined by a radially outwardly extending lower flange 28. Initially, the outer cap component 20 is partially filled with a quantity of a selected uncured but curable sealant or adhesive 30 using a suitable dispenser 32 (FIG. 2). . Although a manual dispenser 32 is shown in FIG. 2, those skilled in the art can use an automated dispenser as needed to place a series of outer cap parts 20 in a desired amount of a selected sealant. It will be understood that it can also be partially satisfied.

  One preferred sealant includes a polysulfide sealant. An exemplary sealant is commercially available from PPG Aerospace, a division of PPG Industries, Pittsburgh, Pennsylvania, under the product name PR1440. Another exemplary sealant is commercially available from the company under the product name PR1422.

As best seen in FIG. 3, the inner collet 34 is partially assembled within the outer cap part 20 with a certain amount of the selected sealant contained within the inverted outer cap part 20. . As shown, the inner collet 34 also defines a substantially closed end wall 36 coupled to the side wall 38, which side wall 38 has a lower or free edge opposite the end wall 36 at its axial end. 40 is determined. Also shown in FIGS. 1 and 3 is that the collet 34 typically has at least three equally spaced inner ribs or radially inwardly extending ribs 42 and the height of the associated sidewall 38 from the lower free edge 40. It is shown to include a plurality of external locking ribs 44 projecting radially outwardly at least about 1/2 below the length. In a preferred form, these locking ribs 44 have an inclined shape that extends downwards (towards the lower free edge 40) by about 1 to 3 degrees.

The inner collet 34 has a sidewall shape that is substantially nested within the matingly sloped side wall 24 of the outer cap component 20 but is slightly sloped to be received with a relatively tight sliding fit. The end walls 22 and 36 are adjacent to each other but spaced apart (shown most clearly in FIG. 5). The outer locking rib 44 of the inner collet 34 engages the outer cap part 20 but is not locked. Further, as shown in FIG. 5, the lower or free edge 40 of the inner collet 34 is disposed below the lower edge 26 and the lower flange 28 of the outer cap part 20 with an axial interval. In this position, a certain amount of sealant 30 fills the space between the end wall 22 of the outer cap part 20 and the end wall 36 of the inner collet 34 and provides a narrow radial space between the respective side walls 24, 38. Partially filled (FIG. 5). In this position, the annular leading edge 46 of the sealant 30 retracts back from the lower edge 26 and associated flange 28 of the outer cap part 20 as can be seen in FIG. It is important that manual contact is impossible.

  In configurations where the insulating sealing cap 10 includes an uncured sealant 30, the cap 10 can be used immediately (as described herein) or to prevent the sealant 30 from curing. The cap 10 containing the uncured sealant 30 can be refrigerated and preferably frozen until ready to be installed. In this regard, the cap 10 is preferably frozen for shipping and / or storage for use. The frozen cap 10 containing the frozen sealant 30 is thawed by short-time heating in a microwave oven or the like so that the sealant 30 melts and can be cured immediately before the use of the cap is desired. It is preferable.

  In use, the assembled insulating sealing cap 10 is placed over a fastening component 12 such as an exemplary nut so that the lower free edge 40 of the inner collet 34 is slidingly fitted against the fastening component 12 while circumscribing it. In effect, it is substantially seated on the substrate 14 so that it is substantially sealed. 1 and 4-5, in the form of a nut having a generally circular base segment 48 so as to preferably engage the inner collet rib 42 and prevent the cap 10 from easily rotating with respect to the fastener 12. The fastening part 12 is shown. Those skilled in the art will recognize and appreciate that the fastening component 12 can take other known forms such as a standard nut lacking a cylindrical base 48, a nut plate mounted on the substrate 14, and the like. Will.

  As can be seen in FIG. 5, after the lower or free edge 40 of the inner collet 34 is initially seated on the substrate 14, the outer cap component 20 is relative to the inner collet 34 (as can be seen in FIGS. 6-7). And move downward toward the substrate 14. The outer cap is thus moved in the direction of the arrow 50 in FIGS. 6 to 7, so that the sealant 30 has a narrow annular space between the end caps 22, 36 and the locking ribs 44 between the side walls 24, 38. Is effectively pushed downward and is pushed outward at the bottom of the outer cap part 20 to form an annular bead 52. As the outer cap part 20 moves further in the direction of the arrow 50 (FIG. 7), the lower edge 26 of the outer cap part 20 on the underside of the flange 28 sits within the bead 52 of this sealant and the substrate 14 is Securely seal and adhere to it. As shown in FIG. 7, the bead 52 can take various geometric shapes in order to cope with a complicated geometric shape fillet formed in the substrate 14. That is, the specific size and / or height of this bead 52 on one side of the fastening part 12 can be larger than the other side, ie the opposite side.

  When the outer cap part 20 is completely moved until the lower edge 26 of the outer cap part 20 is completely seated within the bead 52 of the sealant 30, the locking rib 44 effectively locks the outer cap part 20 onto the inner collet 34. Is done. That is, when the outer cap component 20 moves toward the substrate 14, the engagement amount between the outer cap component 20 and the inner collet 34 is effectively increased and strengthened by the lock rib 44. In the position where the outer cap part 20 is completely seated, the sealants 30, 52 are usually cured in a few hours.

  FIG. 8 shows the substrate 14 in a position to cover the underlying fasteners (not shown in FIG. 8) and the associated access openings formed in the substrate 14 (also not shown in FIG. 8). 1 shows a protective cap 10 of the present invention in an insulatively sealed relationship. In this position, cap 10 effectively insulates one or more fasteners 12 from potential damage due to system components (not shown) or fluids (also not shown) on the cap side of substrate 14. To function. Similarly, the cap 10 allows any system component and / or fluid located on the cap side of the illustrated substrate 14 to access events and / or structures (not shown) and / or substrate access located on the opposite side of the substrate 14. It functions to effectively insulate and seal against potential damage due to one or more fasteners 12 associated with the opening 16.

  Insulating sealing cap 10 provides a sufficiently effective yet relatively thin and lightweight insulating seal to overlay and protect one or more fasteners and associated substrate openings. That is, the sealing cap may be a lightweight molded plastic with sufficient structural rigidity to withstand normal maintenance procedures without breakdown and / or damage that may undesirably interfere with the desired insulation and sealing function. Fig. 3 shows a constructed relatively sturdy cap structure. Optionally, one of the outer cap component 20 and the inner collet 34, eg, the inner collet 34, is constructed of at least partially conductive material, such as at least partially metallic material, to secure the fastening component to the aircraft. A Faraday shield can also be formed that separates from internal components and / or aircraft fuel supplies.

  It will be apparent to those skilled in the art that various further modifications and improvements in and for the improved insulating sealing caps of the present invention and their associated uses. By way of example, the illustrative drawings show the interfitting sidewalls 24, 36 of the outer cap part 20 and inner collet 34 as being generally cylindrical, although those skilled in the art will interfitting. Fastenings in which the side walls 24, 36 are, but are not limited to, non-circular shapes suitable for non-rotating engagement over the fastening part 12 and / or a plurality of closely spaced It will be understood and appreciated that any selected shape may be included, including an elongated shape suitable for fitting over a part, such as an ellipse. Accordingly, the invention is not limited by the foregoing description and accompanying drawings, except as set forth in the appended claims.

10 Insulating sealing cap 12 Fastening component 14 Substrate 16 Substrate opening 18 Threaded bolt 20 Outer cap component 22 Upper end wall 24 Side wall 26 Lower edge 28 Lower flange 34 Inner collet 36 End wall 38 Side wall 40 Lower edge or free edge 42 Internal rib 44 External lock rib 48 Base

Claims (10)

An insulating sealing cap for sealing an opening in a selected substrate,
An outer cap part having a hat-shaped configuration including a top wall further coupled to a hanging side wall coupled to a short flange extending radially outward;
An inner collet having a top wall coupled to a penetrating side wall terminating in a lower edge and having a size and shape that fits in a nested relationship within the outer cap part;
A curable sealant that partially fills the space between the outer cap part and the inner collet;
Including
A lower edge of the inner collet is substantially seatable at a position circumscribing the substrate opening on the substrate;
The outer cap part positioned on the inner collet extrudes the curable sealant between the side wall of the outer cap part and the side wall of the inner collet, so that the substrate and the outer cap part are Moveable toward the substrate to form a bead that adheres to the substrate at a location between the flange and form a curable insulating hermetically sealed connection between the substrate and the flange And
Further comprising a fastening component associated with the substrate opening, wherein the inner collet further comprises at least three plurality of internal ribs for sliding engagement with the fastening component;
An insulating sealing cap characterized by that. The side wall of the outer cap part and the side wall of the inner collet extend downward from the upper wall of the outer cap part and the upper wall of the inner collet;
The insulating sealing cap according to claim 1. A plurality of locking ribs extending between the side wall of the outer cap part and the side wall of the inner collet from the lower edge of the inner collet beyond at least half of the height therebetween;
The insulating sealing cap according to claim 2. The lock rib protrudes radially outward and extends from the upper end of the lock rib to a lower end adjacent to the lower edge of the inner collet so as to expand at an angle of 1 to 3 degrees with respect to the side wall of the inner collet .
The insulating sealing cap according to claim 3. The locking rib is formed externally on the side wall of the inner collet;
The insulating sealing cap according to claim 3. The outer cap part and the inner collet are formed of an insulating material;
The insulating sealing cap according to claim 1. At least one of the outer cap component and the inner collet is formed of a partially conductive material to provide a Faraday shield;
The insulating sealing cap according to claim 6. The curable sealant is retracted from the flange of the outer cap component when the lower edge of the inner collet is seated on the substrate and before the outer cap component moves toward the substrate. Out
The insulating sealing cap according to claim 1. An insulating sealing cap for sealing an opening with an associated fastening component in a selected substrate,
An outer cap part having a hat-shaped configuration including a top wall further coupled to a hanging side wall coupled to a short flange extending radially outward;
To have a top wall that terminates at a lower edge and is coupled to a hanging side wall, and is sized and shaped to fit in a nested relationship within the outer cap part, for non-rotating engagement with the fastening part An inner collet further comprising at least three internal ribs of:
A curable sealant that partially fills the space between the outer cap part and the inner collet;
Including
The inner collet further includes a plurality of locking ribs extending on the outer surface of the side wall from the lower edge of the side wall by at least half of the height of the inner collet, the locking rib projecting radially outwardly; Extending from the upper end of the lock rib to the lower end adjacent to the lower edge of the inner collet so as to expand at an angle of 1 to 3 with respect to the side wall of the inner collet ;
The lower edge of the inner collet is dimensioned and shaped to be substantially seatable at a location circumscribing the substrate opening on the substrate , and the curable sealant is disposed under the inner collet. Before the edge is seated on the substrate, the outer cap part is retracted from the flange of the outer cap part, and the outer cap part located on the inner collet is connected to the side wall of the outer cap part and the inner collet. Extruding the curable sealant between the side wall and forming a bead attached to the substrate at a position between the substrate and the flange of the outer cap component, Movable toward the substrate to form a curable insulating hermetically sealed connection therebetween,
An insulating sealing cap characterized by that. A method of attaching an insulating sealing cap on a selected substrate in a position to seal an opening formed in the substrate, comprising:
Forming an outer cap part having a hat-shaped configuration including a top wall further coupled to a hanging side wall coupled to a radially outwardly extending short flange;
Partially filling the outer cap part with an amount of a selected curable sealant;
Forming an inner collet having an upper wall coupled to a depending side wall;
The inner collet is assembled with the outer cap part by nesting the inner collet into the outer cap part, so that mainly the upper wall of the outer cap part and the upper wall of the inner collet is the arrangement curable sealant in the space between, the curable sealant, defining a lower edge between the side wall of the said side wall of said outer cap component inner collet initially said A step of retracting from the flange of the outer cap part to the back;
Seating a lower edge of the inner collet on the substrate in a substantially circumscribing relationship with the substrate opening;
Moving the outer cap component on the inner collet toward the substrate to extrude the curable sealant to form an insulating sealing bead that engages between a flange of the outer cap component and the substrate; ,
Curing the curable sealant;
A method comprising the steps of:

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